/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// Sep 14, 2000:
//  Fixed serializer to report IO exception directly, instead at
//  the end of document processing.
//  Reported by Patrick Higgins <phiggins@transzap.com>
// Aug 21, 2000:
//  Fixed bug in startDocument not calling prepare.
//  Reported by Mikael Staldal <d96-mst-ingen-reklam@d.kth.se>
// Aug 21, 2000:
//  Added ability to omit DOCTYPE declaration.
// Sep 1, 2000:
//   If no output format is provided the serializer now defaults
//   to ISO-8859-1 encoding. Reported by Mikael Staldal
//   <d96-mst@d.kth.se>

package com.sun.org.apache.xml.internal.serialize;

import com.sun.org.apache.xerces.internal.dom.DOMMessageFormatter;

import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;
import java.util.Enumeration;
import java.util.Locale;

import org.w3c.dom.Attr;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.xml.sax.AttributeList;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;

/**
 * Implements an HTML/XHTML serializer supporting both DOM and SAX
 * pretty serializing. HTML/XHTML mode is determined in the
 * constructor.  For usage instructions see {@link Serializer}.
 * <p>
 * If an output stream is used, the encoding is taken from the
 * output format (defaults to <tt>UTF-8</tt>). If a writer is
 * used, make sure the writer uses the same encoding (if applies)
 * as specified in the output format.
 * <p>
 * The serializer supports both DOM and SAX. DOM serializing is done
 * by calling {@link #serialize} and SAX serializing is done by firing
 * SAX events and using the serializer as a document handler.
 * <p>
 * If an I/O exception occurs while serializing, the serializer
 * will not throw an exception directly, but only throw it
 * at the end of serializing (either DOM or SAX's {@link
 * org.xml.sax.DocumentHandler#endDocument}.
 * <p>
 * For elements that are not specified as whitespace preserving,
 * the serializer will potentially break long text lines at space
 * boundaries, indent lines, and serialize elements on separate
 * lines. Line terminators will be regarded as spaces, and
 * spaces at beginning of line will be stripped.
 * <p>
 * XHTML is slightly different than HTML:
 * <ul>
 * <li>Element/attribute names are lower case and case matters
 * <li>Attributes must specify value, even if empty string
 * <li>Empty elements must have '/' in empty tag
 * <li>Contents of SCRIPT and STYLE elements serialized as CDATA
 * </ul>
 *
 * @deprecated This class was deprecated in Xerces 2.6.2. It is
 * recommended that new applications use JAXP's Transformation API
 * for XML (TrAX) for serializing HTML. See the Xerces documentation
 * for more information.
 * @author <a href="mailto:arkin@intalio.com">Assaf Arkin</a>
 * @see Serializer
 */
public class HTMLSerializer extends BaseMarkupSerializer {

    /**
     * True if serializing in XHTML format.
     */
    private boolean _xhtml;

    public static final String XHTMLNamespace = "http://www.w3.org/1999/xhtml";

    // for users to override XHTMLNamespace if need be.
    private String fUserXHTMLNamespace = null;

    /**
     * Constructs a new HTML/XHTML serializer depending on the value of
     * <tt>xhtml</tt>. The serializer cannot be used without calling
     * {@link #setOutputCharStream} or {@link #setOutputByteStream} first.
     *
     * @param xhtml True if XHTML serializing
     */
    protected HTMLSerializer(boolean xhtml, OutputFormat format) {
        super(format);
        _xhtml = xhtml;
    }

    /**
     * Constructs a new serializer. The serializer cannot be used without
     * calling {@link #setOutputCharStream} or {@link #setOutputByteStream}
     * first.
     */
    public HTMLSerializer() {
        this(false, new OutputFormat(Method.HTML, "ISO-8859-1", false));
    }

    /**
     * Constructs a new serializer. The serializer cannot be used without
     * calling {@link #setOutputCharStream} or {@link #setOutputByteStream}
     * first.
     */
    public HTMLSerializer(OutputFormat format) {
        this(false, format != null ? format : new OutputFormat(Method.HTML, "ISO-8859-1", false));
    }

    /**
     * Constructs a new serializer that writes to the specified writer
     * using the specified output format. If <tt>format</tt> is null,
     * will use a default output format.
     *
     * @param writer The writer to use
     * @param format The output format to use, null for the default
     */
    public HTMLSerializer(Writer writer, OutputFormat format) {
        this(false, format != null ? format : new OutputFormat(Method.HTML, "ISO-8859-1", false));
        setOutputCharStream(writer);
    }

    /**
     * Constructs a new serializer that writes to the specified output
     * stream using the specified output format. If <tt>format</tt>
     * is null, will use a default output format.
     *
     * @param output The output stream to use
     * @param format The output format to use, null for the default
     */
    public HTMLSerializer(OutputStream output, OutputFormat format) {
        this(false, format != null ? format : new OutputFormat(Method.HTML, "ISO-8859-1", false));
        setOutputByteStream(output);
    }

    public void setOutputFormat(OutputFormat format) {
        super.setOutputFormat(format != null ? format : new OutputFormat(Method.HTML, "ISO-8859-1", false));
    }

    // Set  value for alternate XHTML namespace.
    public void setXHTMLNamespace(String newNamespace) {
        fUserXHTMLNamespace = newNamespace;
    } // setXHTMLNamespace(String)

    //-----------------------------------------//
    // SAX content handler serializing methods //
    //-----------------------------------------//

    public void startElement(String namespaceURI, String localName, String rawName, Attributes attrs) throws SAXException {
        int i;
        boolean preserveSpace;
        ElementState state;
        String name;
        String value;
        String htmlName;
        boolean addNSAttr = false;

        try {
            if (_printer == null)
                throw new IllegalStateException(DOMMessageFormatter.formatMessage(DOMMessageFormatter.SERIALIZER_DOMAIN, "NoWriterSupplied", null));

            state = getElementState();
            if (isDocumentState()) {
                // If this is the root element handle it differently.
                // If the first root element in the document, serialize
                // the document's DOCTYPE. Space preserving defaults
                // to that of the output format.
                if (!_started)
                    startDocument((localName == null || localName.length() == 0) ? rawName : localName);
            } else {
                // For any other element, if first in parent, then
                // close parent's opening tag and use the parnet's
                // space preserving.
                if (state.empty)
                    _printer.printText('>');
                // Indent this element on a new line if the first
                // content of the parent element or immediately
                // following an element.
                if (_indenting && !state.preserveSpace && (state.empty || state.afterElement))
                    _printer.breakLine();
            }
            preserveSpace = state.preserveSpace;

            // Do not change the current element state yet.
            // This only happens in endElement().

            // As per SAX2, the namespace URI is an empty string if the element has no
            // namespace URI, or namespaces is turned off. The check against null protects
            // against broken SAX implementations, so I've left it there. - mrglavas
            boolean hasNamespaceURI = (namespaceURI != null && namespaceURI.length() != 0);

            // SAX2: rawName (QName) could be empty string if
            // namespace-prefixes property is false.
            if (rawName == null || rawName.length() == 0) {
                rawName = localName;
                if (hasNamespaceURI) {
                    String prefix;
                    prefix = getPrefix(namespaceURI);
                    if (prefix != null && prefix.length() != 0)
                        rawName = prefix + ":" + localName;
                }
                addNSAttr = true;
            }
            if (!hasNamespaceURI)
                htmlName = rawName;
            else {
                if (namespaceURI.equals(XHTMLNamespace) || (fUserXHTMLNamespace != null && fUserXHTMLNamespace.equals(namespaceURI)))
                    htmlName = localName;
                else
                    htmlName = null;
            }

            // XHTML: element names are lower case, DOM will be different
            _printer.printText('<');
            if (_xhtml)
                _printer.printText(rawName.toLowerCase(Locale.ENGLISH));
            else
                _printer.printText(rawName);
            _printer.indent();

            // For each attribute serialize it's name and value as one part,
            // separated with a space so the element can be broken on
            // multiple lines.
            if (attrs != null) {
                for (i = 0; i < attrs.getLength(); ++i) {
                    _printer.printSpace();
                    name = attrs.getQName(i).toLowerCase(Locale.ENGLISH);
                    value = attrs.getValue(i);
                    if (_xhtml || hasNamespaceURI) {
                        // XHTML: print empty string for null values.
                        if (value == null) {
                            _printer.printText(name);
                            _printer.printText("=\"\"");
                        } else {
                            _printer.printText(name);
                            _printer.printText("=\"");
                            printEscaped(value);
                            _printer.printText('"');
                        }
                    } else {
                        // HTML: Empty values print as attribute name, no value.
                        // HTML: URI attributes will print unescaped
                        if (value == null) {
                            value = "";
                        }
                        if (!_format.getPreserveEmptyAttributes() && value.length() == 0)
                            _printer.printText(name);
                        else if (HTMLdtd.isURI(rawName, name)) {
                            _printer.printText(name);
                            _printer.printText("=\"");
                            _printer.printText(escapeURI(value));
                            _printer.printText('"');
                        } else if (HTMLdtd.isBoolean(rawName, name))
                            _printer.printText(name);
                        else {
                            _printer.printText(name);
                            _printer.printText("=\"");
                            printEscaped(value);
                            _printer.printText('"');
                        }
                    }
                }
            }
            if (htmlName != null && HTMLdtd.isPreserveSpace(htmlName))
                preserveSpace = true;

            if (addNSAttr) {
                Enumeration keys;

                keys = _prefixes.keys();
                while (keys.hasMoreElements()) {
                    _printer.printSpace();
                    value = (String) keys.nextElement();
                    name = (String) _prefixes.get(value);
                    if (name.length() == 0) {
                        _printer.printText("xmlns=\"");
                        printEscaped(value);
                        _printer.printText('"');
                    } else {
                        _printer.printText("xmlns:");
                        _printer.printText(name);
                        _printer.printText("=\"");
                        printEscaped(value);
                        _printer.printText('"');
                    }
                }
            }

            // Now it's time to enter a new element state
            // with the tag name and space preserving.
            // We still do not change the curent element state.
            state = enterElementState(namespaceURI, localName, rawName, preserveSpace);

            // Prevents line breaks inside A/TD

            if (htmlName != null && (htmlName.equalsIgnoreCase("A") || htmlName.equalsIgnoreCase("TD"))) {
                state.empty = false;
                _printer.printText('>');
            }

            // Handle SCRIPT and STYLE specifically by changing the
            // state of the current element to CDATA (XHTML) or
            // unescaped (HTML).
            if (htmlName != null && (rawName.equalsIgnoreCase("SCRIPT") || rawName.equalsIgnoreCase("STYLE"))) {
                if (_xhtml) {
                    // XHTML: Print contents as CDATA section
                    state.doCData = true;
                } else {
                    // HTML: Print contents unescaped
                    state.unescaped = true;
                }
            }
        } catch (IOException except) {
            throw new SAXException(except);
        }
    }

    public void endElement(String namespaceURI, String localName, String rawName) throws SAXException {
        try {
            endElementIO(namespaceURI, localName, rawName);
        } catch (IOException except) {
            throw new SAXException(except);
        }
    }

    public void endElementIO(String namespaceURI, String localName, String rawName) throws IOException {
        ElementState state;
        String htmlName;

        // Works much like content() with additions for closing
        // an element. Note the different checks for the closed
        // element's state and the parent element's state.
        _printer.unindent();
        state = getElementState();

        if (state.namespaceURI == null || state.namespaceURI.length() == 0)
            htmlName = state.rawName;
        else {
            if (state.namespaceURI.equals(XHTMLNamespace) || (fUserXHTMLNamespace != null && fUserXHTMLNamespace.equals(state.namespaceURI)))
                htmlName = state.localName;
            else
                htmlName = null;
        }

        if (_xhtml) {
            if (state.empty) {
                _printer.printText(" />");
            } else {
                // Must leave CData section first
                if (state.inCData)
                    _printer.printText("]]>");
                // XHTML: element names are lower case, DOM will be different
                _printer.printText("</");
                _printer.printText(state.rawName.toLowerCase(Locale.ENGLISH));
                _printer.printText('>');
            }
        } else {
            if (state.empty)
                _printer.printText('>');
            // This element is not empty and that last content was
            // another element, so print a line break before that
            // last element and this element's closing tag.
            // [keith] Provided this is not an anchor.
            // HTML: some elements do not print closing tag (e.g. LI)
            if (htmlName == null || !HTMLdtd.isOnlyOpening(htmlName)) {
                if (_indenting && !state.preserveSpace && state.afterElement)
                    _printer.breakLine();
                // Must leave CData section first (Illegal in HTML, but still)
                if (state.inCData)
                    _printer.printText("]]>");
                _printer.printText("</");
                _printer.printText(state.rawName);
                _printer.printText('>');
            }
        }
        // Leave the element state and update that of the parent
        // (if we're not root) to not empty and after element.
        state = leaveElementState();
        // Temporary hack to prevent line breaks inside A/TD
        if (htmlName == null || (!htmlName.equalsIgnoreCase("A") && !htmlName.equalsIgnoreCase("TD")))

            state.afterElement = true;
        state.empty = false;
        if (isDocumentState())
            _printer.flush();
    }

    //------------------------------------------//
    // SAX document handler serializing methods //
    //------------------------------------------//

    public void characters(char[] chars, int start, int length) throws SAXException {
        ElementState state;

        try {
            // HTML: no CDATA section
            state = content();
            state.doCData = false;
            super.characters(chars, start, length);
        } catch (IOException except) {
            throw new SAXException(except);
        }
    }

    public void startElement(String tagName, AttributeList attrs) throws SAXException {
        int i;
        boolean preserveSpace;
        ElementState state;
        String name;
        String value;

        try {
            if (_printer == null)
                throw new IllegalStateException(DOMMessageFormatter.formatMessage(DOMMessageFormatter.SERIALIZER_DOMAIN, "NoWriterSupplied", null));

            state = getElementState();
            if (isDocumentState()) {
                // If this is the root element handle it differently.
                // If the first root element in the document, serialize
                // the document's DOCTYPE. Space preserving defaults
                // to that of the output format.
                if (!_started)
                    startDocument(tagName);
            } else {
                // For any other element, if first in parent, then
                // close parent's opening tag and use the parnet's
                // space preserving.
                if (state.empty)
                    _printer.printText('>');
                // Indent this element on a new line if the first
                // content of the parent element or immediately
                // following an element.
                if (_indenting && !state.preserveSpace && (state.empty || state.afterElement))
                    _printer.breakLine();
            }
            preserveSpace = state.preserveSpace;

            // Do not change the current element state yet.
            // This only happens in endElement().

            // XHTML: element names are lower case, DOM will be different
            _printer.printText('<');
            if (_xhtml)
                _printer.printText(tagName.toLowerCase(Locale.ENGLISH));
            else
                _printer.printText(tagName);
            _printer.indent();

            // For each attribute serialize it's name and value as one part,
            // separated with a space so the element can be broken on
            // multiple lines.
            if (attrs != null) {
                for (i = 0; i < attrs.getLength(); ++i) {
                    _printer.printSpace();
                    name = attrs.getName(i).toLowerCase(Locale.ENGLISH);
                    value = attrs.getValue(i);
                    if (_xhtml) {
                        // XHTML: print empty string for null values.
                        if (value == null) {
                            _printer.printText(name);
                            _printer.printText("=\"\"");
                        } else {
                            _printer.printText(name);
                            _printer.printText("=\"");
                            printEscaped(value);
                            _printer.printText('"');
                        }
                    } else {
                        // HTML: Empty values print as attribute name, no value.
                        // HTML: URI attributes will print unescaped
                        if (value == null) {
                            value = "";
                        }
                        if (!_format.getPreserveEmptyAttributes() && value.length() == 0)
                            _printer.printText(name);
                        else if (HTMLdtd.isURI(tagName, name)) {
                            _printer.printText(name);
                            _printer.printText("=\"");
                            _printer.printText(escapeURI(value));
                            _printer.printText('"');
                        } else if (HTMLdtd.isBoolean(tagName, name))
                            _printer.printText(name);
                        else {
                            _printer.printText(name);
                            _printer.printText("=\"");
                            printEscaped(value);
                            _printer.printText('"');
                        }
                    }
                }
            }
            if (HTMLdtd.isPreserveSpace(tagName))
                preserveSpace = true;

            // Now it's time to enter a new element state
            // with the tag name and space preserving.
            // We still do not change the curent element state.
            state = enterElementState(null, null, tagName, preserveSpace);

            // Prevents line breaks inside A/TD
            if (tagName.equalsIgnoreCase("A") || tagName.equalsIgnoreCase("TD")) {
                state.empty = false;
                _printer.printText('>');
            }

            // Handle SCRIPT and STYLE specifically by changing the
            // state of the current element to CDATA (XHTML) or
            // unescaped (HTML).
            if (tagName.equalsIgnoreCase("SCRIPT") || tagName.equalsIgnoreCase("STYLE")) {
                if (_xhtml) {
                    // XHTML: Print contents as CDATA section
                    state.doCData = true;
                } else {
                    // HTML: Print contents unescaped
                    state.unescaped = true;
                }
            }
        } catch (IOException except) {
            throw new SAXException(except);
        }
    }

    public void endElement(String tagName) throws SAXException {
        endElement(null, null, tagName);
    }

    //------------------------------------------//
    // Generic node serializing methods methods //
    //------------------------------------------//

    /**
     * Called to serialize the document's DOCTYPE by the root element.
     * The document type declaration must name the root element,
     * but the root element is only known when that element is serialized,
     * and not at the start of the document.
     * <p>
     * This method will check if it has not been called before ({@link #_started}),
     * will serialize the document type declaration, and will serialize all
     * pre-root comments and PIs that were accumulated in the document
     * (see {@link #serializePreRoot}). Pre-root will be serialized even if
     * this is not the first root element of the document.
     */
    protected void startDocument(String rootTagName) throws IOException {
        StringBuffer buffer;

        // Not supported in HTML/XHTML, but we still have to switch
        // out of DTD mode.
        _printer.leaveDTD();
        if (!_started) {
            // If the public and system identifiers were not specified
            // in the output format, use the appropriate ones for HTML
            // or XHTML.
            if (_docTypePublicId == null && _docTypeSystemId == null) {
                if (_xhtml) {
                    _docTypePublicId = HTMLdtd.XHTMLPublicId;
                    _docTypeSystemId = HTMLdtd.XHTMLSystemId;
                } else {
                    _docTypePublicId = HTMLdtd.HTMLPublicId;
                    _docTypeSystemId = HTMLdtd.HTMLSystemId;
                }
            }

            if (!_format.getOmitDocumentType()) {
                // XHTML: If public identifier and system identifier
                //  specified, print them, else print just system identifier
                // HTML: If public identifier specified, print it with
                //  system identifier, if specified.
                // XHTML requires that all element names are lower case, so the
                // root on the DOCTYPE must be 'html'. - mrglavas
                if (_docTypePublicId != null && (!_xhtml || _docTypeSystemId != null)) {
                    if (_xhtml) {
                        _printer.printText("<!DOCTYPE html PUBLIC ");
                    } else {
                        _printer.printText("<!DOCTYPE HTML PUBLIC ");
                    }
                    printDoctypeURL(_docTypePublicId);
                    if (_docTypeSystemId != null) {
                        if (_indenting) {
                            _printer.breakLine();
                            _printer.printText("                      ");
                        } else
                            _printer.printText(' ');
                        printDoctypeURL(_docTypeSystemId);
                    }
                    _printer.printText('>');
                    _printer.breakLine();
                } else if (_docTypeSystemId != null) {
                    if (_xhtml) {
                        _printer.printText("<!DOCTYPE html SYSTEM ");
                    } else {
                        _printer.printText("<!DOCTYPE HTML SYSTEM ");
                    }
                    printDoctypeURL(_docTypeSystemId);
                    _printer.printText('>');
                    _printer.breakLine();
                }
            }
        }

        _started = true;
        // Always serialize these, even if not te first root element.
        serializePreRoot();
    }

    /**
     * Called to serialize a DOM element. Equivalent to calling {@link
     * #startElement}, {@link #endElement} and serializing everything
     * inbetween, but better optimized.
     */
    protected void serializeElement(Element elem) throws IOException {
        Attr attr;
        NamedNodeMap attrMap;
        int i;
        Node child;
        ElementState state;
        boolean preserveSpace;
        String name;
        String value;
        String tagName;

        tagName = elem.getTagName();
        state = getElementState();
        if (isDocumentState()) {
            // If this is the root element handle it differently.
            // If the first root element in the document, serialize
            // the document's DOCTYPE. Space preserving defaults
            // to that of the output format.
            if (!_started)
                startDocument(tagName);
        } else {
            // For any other element, if first in parent, then
            // close parent's opening tag and use the parnet's
            // space preserving.
            if (state.empty)
                _printer.printText('>');
            // Indent this element on a new line if the first
            // content of the parent element or immediately
            // following an element.
            if (_indenting && !state.preserveSpace && (state.empty || state.afterElement))
                _printer.breakLine();
        }
        preserveSpace = state.preserveSpace;

        // Do not change the current element state yet.
        // This only happens in endElement().

        // XHTML: element names are lower case, DOM will be different
        _printer.printText('<');
        if (_xhtml)
            _printer.printText(tagName.toLowerCase(Locale.ENGLISH));
        else
            _printer.printText(tagName);
        _printer.indent();

        // Lookup the element's attribute, but only print specified
        // attributes. (Unspecified attributes are derived from the DTD.
        // For each attribute print it's name and value as one part,
        // separated with a space so the element can be broken on
        // multiple lines.
        attrMap = elem.getAttributes();
        if (attrMap != null) {
            for (i = 0; i < attrMap.getLength(); ++i) {
                attr = (Attr) attrMap.item(i);
                name = attr.getName().toLowerCase(Locale.ENGLISH);
                value = attr.getValue();
                if (attr.getSpecified()) {
                    _printer.printSpace();
                    if (_xhtml) {
                        // XHTML: print empty string for null values.
                        if (value == null) {
                            _printer.printText(name);
                            _printer.printText("=\"\"");
                        } else {
                            _printer.printText(name);
                            _printer.printText("=\"");
                            printEscaped(value);
                            _printer.printText('"');
                        }
                    } else {
                        // HTML: Empty values print as attribute name, no value.
                        // HTML: URI attributes will print unescaped
                        if (value == null) {
                            value = "";
                        }
                        if (!_format.getPreserveEmptyAttributes() && value.length() == 0)
                            _printer.printText(name);
                        else if (HTMLdtd.isURI(tagName, name)) {
                            _printer.printText(name);
                            _printer.printText("=\"");
                            _printer.printText(escapeURI(value));
                            _printer.printText('"');
                        } else if (HTMLdtd.isBoolean(tagName, name))
                            _printer.printText(name);
                        else {
                            _printer.printText(name);
                            _printer.printText("=\"");
                            printEscaped(value);
                            _printer.printText('"');
                        }
                    }
                }
            }
        }
        if (HTMLdtd.isPreserveSpace(tagName))
            preserveSpace = true;

        // If element has children, or if element is not an empty tag,
        // serialize an opening tag.
        if (elem.hasChildNodes() || !HTMLdtd.isEmptyTag(tagName)) {
            // Enter an element state, and serialize the children
            // one by one. Finally, end the element.
            state = enterElementState(null, null, tagName, preserveSpace);

            // Prevents line breaks inside A/TD
            if (tagName.equalsIgnoreCase("A") || tagName.equalsIgnoreCase("TD")) {
                state.empty = false;
                _printer.printText('>');
            }

            // Handle SCRIPT and STYLE specifically by changing the
            // state of the current element to CDATA (XHTML) or
            // unescaped (HTML).
            if (tagName.equalsIgnoreCase("SCRIPT") || tagName.equalsIgnoreCase("STYLE")) {
                if (_xhtml) {
                    // XHTML: Print contents as CDATA section
                    state.doCData = true;
                } else {
                    // HTML: Print contents unescaped
                    state.unescaped = true;
                }
            }
            child = elem.getFirstChild();
            while (child != null) {
                serializeNode(child);
                child = child.getNextSibling();
            }
            endElementIO(null, null, tagName);
        } else {
            _printer.unindent();
            // XHTML: Close empty tag with ' />' so it's XML and HTML compatible.
            // HTML: Empty tags are defined as such in DTD no in document.
            if (_xhtml)
                _printer.printText(" />");
            else
                _printer.printText('>');
            // After element but parent element is no longer empty.
            state.afterElement = true;
            state.empty = false;
            if (isDocumentState())
                _printer.flush();
        }
    }

    protected void characters(String text) throws IOException {
        ElementState state;

        // HTML: no CDATA section
        state = content();
        super.characters(text);
    }

    protected String getEntityRef(int ch) {
        return HTMLdtd.fromChar(ch);
    }

    protected String escapeURI(String uri) {
        int index;

        // XXX  Apparently Netscape doesn't like if we escape the URI
        //      using %nn, so we leave it as is, just remove any quotes.
        index = uri.indexOf("\"");
        if (index >= 0)
            return uri.substring(0, index);
        else
            return uri;
    }

}
